Rates of women who are opting for preventive mastectomies, such as Angeline Jolie, have increased by an estimated 50 percent in recent years, experts say. But many doctors are puzzled because the operation doesn't carry a 100 percent guarantee, it's major surgery -- and women have other options, from a once-a-day pill to careful monitoring.

"This embargo will help us protect the American public and prevent introduction of SARS in the United States," Health and Human Services Secretary Tommy Thompson said Tuesday.

While scientists have not found unequivocal evidence that the small tree-dwelling mammal is responsible for transmitting severe acute respiratory syndrome to humans, they have found the SARS virus in civets and China has ordered the killing of thousands of the animals.

It wasn't clear how many civets, regarded as a delicacy in southern China, are imported into the United States.

Thompson said noninfectious civet products, such as taxidermied animals, and civets imported for educational or scientific purposes, would not be affected by the ban.

SARS emerged in Guangdong, southern China, in late 2002 and sickened more than 8,000 people worldwide before subsiding in June. The disease has killed nearly 800 people.